U.S. Pat. No. 5,367,093 describes a method for the preparation of the miticidal phenylhydrazine derivative, isopropyl-2-(4-methoxy-[1,1'-biphenyl]-3-yl)hydrazine carboxylate (bifenazate), using a six-step procedure which comprises the undesirable steps of preparation and reduction of a diazonium salt.
Certain phenylhydrazine derivatives can be prepared using the methods described in U.S. Pat. No. 4,864,032 (amination of Grignard); in Mitchell, J. Org. Chem. 59: 682 (1994) (amination of electron-rich arenes); and in Lenarsic, J. Org. Chem. 64: 2558 (1999) (by electrophilic azodicarboxylates).
It is the purpose of this invention to provide new intermediates useful in the preparation of bifenazate. It is also a purpose of this invention to provide a new method for the preparation of bifenazate.